The present invention relates to a method or process of locating pairs of curved parallel lines in an image. It applies more particularly to the recognition of vessels in digital angiography but may also be applied to the analysis of aerial views for recognizing rivers and roads.
Angiography is a process for the visual analysis of blood vessels. Its principle consists in X raying the observation zone, before then after, the injection of a product opaque to X rays. The logarithmic difference of these two images allows a well contrasted image of the zones to be obtained of the vascular network where the product has spread, if there has been no movement between the two images. The support for these images is formed either by a photographic film or by a digital image memory.
The photographic film is used in traditional angiography, it has the advantage of providing images of high definition but has the drawback of requiring fairly long operating times, related to the processing of the photographic support.
The digital image memory is used in digital angiography, it allows an analysis to be made practically in real time but it supplies an image or poorer definition than that obtained in traditional angiography.